Studies on pyrrolidinone. Synthesis of aza analogs of podophyllotoxin and related compounds

The Friedel-Crafts cyclisation of N-benzhydrylpyroglutamic acids whose aromatic rings are substituted by methoxy or methylenedioxy groups gives podophyllotoxin analogs whose lactone ring was changed to a lactam.     

Antitumor agents. I. DNA topoisomerase II inhibitory activity and the structural relationship of podophyllotoxin derivatives as antitumor agents.

Various podophyllotoxin derivatives from desoxypodophyllotoxin (DPT) were synthesized to examine the structural relationships between the biological significance (cytotoxic effect, effects on DNA topoisomerase II and tubulin polymerization) in vitro and antitumor activity in vivo (L 1210). An intact 6,7-methylenedioxy group of DPT is necessary to inhibit tubulin polymerization and topoisomerase II. 4'-Phenolic hydroxyl group of DPT is essential to inhibit DNA topoisomerase II and the inhibitory effect on DNA topoisomerase II contributes to a high cytotoxicity. The introduction of an aminoalkoxy group at 1-position of DPT enhances the inhibitory activity against DNA topoisomerase II and cytotoxic effect, causing the inhibitory activity against tubulin polymerization to disappear. The results of antitumor test in mice bearing L 1210 on podophyllotoxin derivatives suggest the following: 1) the strong cytotoxic effect itself is not a good indication of antitumor activity in vivo as long as it is associated with inhibition of tubulin polymerization. DNA topoisomerase II inhibitory effect contributes to an antitumor activity in vivo; 2) detailed measurements of cytotoxicity and inhibition on DNA topoisomerase II and tubulin polymerization in vitro are necessary to evaluate podophyllotoxin derivatives.     

Studies on antitumor agents. IX. Synthesis of 3'-O-benzyl-2'-deoxy-5-trifluoromethyluridine

A practical synthesis of 3'-O-benzyl-2'-deoxy-5-trifluoromethyluridine (1), a candidate antitumor agent for clinical testing, was developed from 2'-deoxy-5-iodouridine (3). Benzylation of 2'-deoxy-5-iodo-5'-O-trityluridine (14) with benzyl bromide and sodium hydride in tetrahydrofuran gave the 3'-O-derivative (16). Benzoylation of 16 afforded the N3-benzoyl derivative (17). Coupling of 17 with trifluoromethylcopper, prepared from bromotrifluoromethane and copper powder in the presence of 4-dimethylaminopyridine, gave the 5-trifluoromethyl derivative (19) minimally contaminated with the 5-pentafluoroethyl compound. Deprotection of 19 furnished 1.     

Studies on gastric antiulcer active agents. II. Synthesis of tetrazole alkanamides and related compounds

A series of tetrazole alkanamides was synthesized and tested for antiulcer activity against acetic acid-induced gastric ulcer in rats. These compounds were prepared by the reaction of tetrazole alkanoic acids and various amines by the mixed anhydride method or acid chloride method. Among them, 3-[(1-ethyl-5-tetrazolyl)methylthio]propionamide (IIn) was found to have the most potent activity. The structure-activity relationships are discussed.     

Synthesis of new benzopyrans related to podophyllotoxin

Mannich bases of types 1 or 8 , which are readily synthesized by condensation of 3,4-methylenedioxyphenol with aromatic aldehydes and pyrrolidine or piperazine, react with cyclic and acyclic β-diketones to yield benzopyrans. These benzopyrans are structurally similar to podophyllotoxin and like this drug some of the benzopyrans show in vivo anti-leukemic action in mice.     

Synthesis and antitumor activity of novel podophyllotoxin derivatives

In order to find compounds with superior bioactivity and overcoming multidrug resistance,a novel series of 4β-N-substituted podophyllotoxin derivatives were synthesized and evaluated as potential antitumor agents.Seven novel podophyllotoxin derivatives were synthesized by linking-4β-amino-4-deoxypodophyllotoxin with alcohols through maleic acid and tested against K562 and K562/A02 using MTT assay in vitro.     

Synthesis of methyl 2,6- and 3,6-dideoxy-α-L-arabino-hexopyranosides and methyl 4,6-dideoxy-α-L-lyxo-hexopyranoside

A convenient method of synthesizing methyl 2,6- and 3,6-dideoxy-α-L-arabinohexopyranosides and of methyl 4,6-dideoxy-α-L-lyxo-hexopyranoside is proposed. Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 320–322, May–June, 1990.     

Studies on antidiabetic agents. X. Synthesis and biological activities of pioglitazone and related compounds

Various analogues of a new antidiabetic agent, pioglitazone (AD-4833, U-72107), were synthesized in order to study in more detail the structure-activity relationships of this class of drug. 5-(4-Pyridylalkylthiobenzyl)-2,4-thiazolidinediones (I), thia-analogues of pioglitazone, were prepared via Meerwein arylation of the alkylthioanilines (IV). 5-(4-Pyridylalkoxybenzylidene)-2,4-thiazolidinediones (IIa) and related heterocyclic analogues (IIb) were synthesized by Knoevenagel condensation of the aldehydes (VIII) with the corresponding azolidinones. Compounds I and II were evaluated for hypoglycemic and hypolipidemic activity in genetically obese and diabetic yellow KK (KKAy) mice. Several 5-[4-[2-(2-pyridyl)ethoxy]-benzylidene]-2,4- thiazolidinediones (IIa) were equipotent to pioglitazone. However, the thia-analogues (I) and the benzylideneheterocycles (IIb) had decreased activity. Catalytic hydrogenation of the 5-benzylidene analogue (14) was found to be a convenient new synthetic method for pioglitazone. The configuration of 14 is also discussed.     

Studies on cardiotonic agents. II. Synthesis of novel phthalazine and 1,2,3-benzotriazine derivatives

A series of phthalazine and 1,2,3-benzotriazine derivatives which have heterocyclylpiperidino groups was synthesized and tested for cardiotonic activity in anesthetized dogs. Several 6,7-dimethoxyphthalazine derivatives showed relatively potent cardiotonic activity comparable to that of amrinone.     

Studies on antiallergy agents. III. Synthesis of 2-anilino-1,6-dihydro-6-oxo-5-pyrimidinecarboxylic acids and related compounds

A series of 2-anilino-1,6-dihydro-6-oxo-5-pyrimidinecarboxylic acids with various substituents was synthesized and evaluated in the rat passive cutaneous anaphylaxis test for antiallergic activity. High activity by intraperitoneal and oral administrations was observed for the 3-trifluoromethyl and 2-alkoxyanilino derivatives (64, 79, 81, 82 and 85). Structure-activity relationships are discussed.